The drive units for marine propulsion devices, including outboard motors and stern drives, are typically supported from the transom located as the stern of the boat by a mounting assembly. Various types of non-adjustable mounting assemblies are known, such as the boat propelling attachment described in U.S. Pat. No. 570,613 to Smith, incorporated herein by reference. Although an outboard motor mounted directly on the boat transom may be trimmed by tilting, a non-adjustable mount restricts the amount of vertical movement of the outboard motor. To overcome this problem, adjustable mounting assemblies have been invented which not only allow for more vertical movement and trim, but also position the motor aft of the stern of the boat, thus improving high speed handling. These transom extension mounting assemblies are mounted to the transom of the boat supporting the outboard motor aft of the boat transom. The relocation of the motor aft of the transom improves the high speed handling characteristics of most boats. This also improves the maneuverability of slow speed turning and docking, resulting in drastic improvements for the operator and safety of the passengers. Transom extension mounting assemblies are used increasingly on high performance boats powdered by outboard motors, where a lower position of the motor improves initial boat acceleration and a higher position enhances top speed by reducing gear case drag, and draft, thereby enhancing shallow water performance. The raising of the motor while underway enhances a steadier, more stable ride allowing the cutting edge of the hull to perform as its engineered design. In short, transom extensions increase fuel economy, provide less drag, increase rpm's and horsepower.
One type of transom extension mounting assembly comprises a parallelogram linkage arrangement between the motor and the transom of the boat. Such systems are generally described in U.S. Pat. No. 4,890,811 to Ehni; U.S. Pat. No. 4,682,961 to Nakahama; U.S. Pat. No. 4,861,292 to Griffiths, et al.; and U.S. Pat. No. 4,842,559 to Litjens et al.; all of which are incorporated herein by reference.
The transom extension mounting assembly of the Ehni patent generally describes a mounting device positioned between the boat and the outboard motor including a parallelogram linkage having a front bracket for securement to the transom and a rear bracket on which the outboard motor is secured. For raising and lowering the parallelogram linkage and outboard motor mounted thereon, a hydraulic cylinder is secured to the front bracket and an extending piston rod is mounted on the rear bracket. Upon acceleration, when the bow of the boat tends to rise, the desired boat ride angle may be adjusted by raising or lowering the parallelogram linkage. Also, in shallow water, the outboard motor may be raised so that the propeller is above the lower surface of the boat.
The transom extension mounting assembly of the Nakahama patent describes a parallelogram linkage for trimming the propeller and tilting the motor up, without increasing the effective length of the water craft.
Another type of mounting assembly comprises a slidably mounted motor mounting plate. Such systems are generally described in U.S. Pat. No. 4,907,993 to Thompson; U.S. Pat. No. 4,482,330 to Cook; U.S. Pat. No. 4,232,627 to Glenn et al.; U.S. Pat. No. 4,624,438 to Goodman, Jr.; and U.S. Pat. No. 5,100,349 to Perkins et al., all of which are incorporated herein by reference.
The mounting assembly of the Thompson patent generally describes an apparatus for mounting an outboard motor including a transom bracket and motor mounting plate slidably mounted in channels located on the inside surface of the rearwardly extending side plates of the transom bracket. A waterproof marine electromechanical unit having an activating rod secured to the mounting plate raises and lowers the mounting plate.
However, there are problems associated with each of these type of mounting assemblies.
A first problem is with mounting assemblies which mount on outboard motor directly on a boat transom at a fixed height. These types of mounting assemblies do not allow any of the benefits of vertical movement of the motor, other than the limited movement inherent in the trimming operation.
The parallelogram linkage assemblies used for raising and lowering the outboard motor, or for tilting and trimming the outboard motor have the disadvantage of causing increased weight near the stern of the boat, an effect which decreases the performance of the water craft by causing the stern of the boat to sit lower in the water, not only during idle conditions, but also during operation. The lower stern position causes the outboard motor to add increased drag and resistance, the very problem which the transom extension mounting assembly is trying to overcome. During any running speeds, this type of assembly causes the boat to squat towards the aft of the boat where the outboard motor is mounted, making a large wake which is unsafe for passing boats, and causes the bow to raise, blocking the operators view. This same disadvantage arises in the motor mounting assemblies in which the motor mounting plate is slidably mounted on a transom bracket.
An additional problem with parallelogram linkage mounting assemblies is that the parallelogram linkage assembly has numerous exposed moving parts, subject to salt water corrosion due to continuous contact with the salt water and air. In addition, the exposed assembly fails to provide protection for the hydraulic cylinder or other control systems.
A further problem exists with parallelogram linkage mounting assemblies regarding personal safety. An operator's or passenger's hands or feet may become trapped during the adjustment of the moving arms of the parallelogram linkage, especially when attempting to work on the outboard motor or climbing into the stern of the boat.
An additional problem arises in that none of the above-mentioned systems have a bottom panel on the transom bracket, therefore they fail to provide any protection from splashing and water intrusion into the boat during operation and especially while backing down during fishing. A bottom panel is a major factor in preventing the boat from squatting when underway and preventing the carburetors from becoming swamped.
Another problem arises with the above-mentioned systems when an operator needs to access the motor, since there is no top surface area on the mounting assemblies upon which the operator may sit or stand. This problem often results in the operator having to enter the water, even for minor maintenance.
Another problem is that the above-mentioned systems lack a top mounted platform, beneficial for both the operator accessing the motor and for swimmers and the like entering the boat.
Another problem is that since the above-mentioned systems do not provide any flotation near the stern of the boat, an operator would be detoured from standing near the transom to take the engine cowling off to check for an obvious mechanical failure. Without flotation, the additional weight of an adult may cause the powerhead to become swamped and damaged with the cowling removed.
One possible solution to these problems is to provide a system wherein the transom extension assembly adds flotation to the stern of the boat rather than added weight, to provide compensation for the weight of the motor.
Another possible solution to these problems is to provide a system with no exposed critical moving parts or control devices which could corrode or become damaged due to the salt water and air.
Another possible solution to these problems is to provide a system wherein the chance of an operator or passenger becoming injured during routine motor maintenance or climbing into the boat is reduced.
Another possible solution to these problems is to provide a system wherein vertical movement of the outboard motor is accomplished by installation of a simple, streamlined, color-coordinated integral unit, adapted for use on most boat transoms which does not detract from the aesthetic appearance of the boat.
Another possible solution to these problems is to provide a system wherein a bottom panel to the transom extension is provided to reduce splashing and water intrusion into the stern of the boat, preventing the boat from squatting while underway, and preventing the carburetors from becoming swamped.
Another possible solution to these problems is to provide a system wherein an operator can access the motor without entering the water by sitting on a top surface of the mounting assembly.
Another possible solution to these problems is to provide a system with a top mounted platform, beneficial for both the operator accessing the motor and for swimmers and the like entering the boat.
Another possible solution to these problems is to provide a system with flotation near the stern of the boat, so that an operator may stand near the transom to take the engine cowling off and check for an obvious mechanical failure without the fear of swamping the powerhead. A system provided with flotation near the stern of the boat would also aid in rope starting the engine.
Thus, there has been a need in the art for a system that provides flotation near the stern of the boat rather than added weight, to compensate for the weight of the motor.
There is an additional need in the art for a system in which no exposed critical moving parts or control devices are subject to corrosion or become damaged due to the salt water and air.
There is an additional need in the art for a system which does not increase the chance of an operator or passenger becoming injured during routine motor maintenance or climbing into the boat.
There is an additional need in the art for a system which provides vertical movement of the outboard motor through installation of a simple, streamlined, color-coordinated integral unit, adapted for use on most boat transoms, which does not detract from the aesthetic appearance of the boat.
There is an additional need in the art to provide a system wherein a bottom panel to the transom extension is provided to reduce splashing and water intrusion into the stern of the boat, prevent the boat from squatting while underway, and prevent the carburetors from becoming swamped and stalling the motor, especially during heavy sea conditions.
There is an additional need in the art to provide a system which allows easy access to the motor by allowing the operator to sit or stand on a top surface of the mounting assembly.
There is an additional need in the art to provide a system with a top mounted platform for use by both the operator and others in accessing the motor or entering the boat.